ASHLEY, Mike: The Time Machines: The Story of the Science-Fiction Pulp Magazines from the Beginning to 1950. The History of the Science-Fiction Magazine, Volume I. 2000. Liverpool University Press, UK. – 312 стр.

ASHLEY, Mike: Gateways to Forever. The Story of the Science-Fiction Magazines from 1970 to 1980. The History of the Science-Fiction Magazine. Volume III. 2007. Liverpool University Press, UK. – 504 стр.